It is proposed to continue to operate and to extend the capabilities of the Rockefeller Biotechnology Mass Spectrometric Research Resource. Emphasis will be placed upon the mass spectrometry of high molecular weight, involatile materials of biomedical interest. A new focus of the Resource will involve the use of tandem mass spectrometry (MS-MS) as an analytical tool for the detailed structural analysis of biomolecules. Two separate approaches to tandem mass spectrometry will be followed involving (1) the acquisition and application of a commercial four-sector mass spectrometer using liquid secondary ionization mass spectrometry (fast atom bombardment) and collision induced dissociation, and (2) the construction and development of a time-of-flight tandem mass spectrometer using resonance enhanced multiphoton ionization and laser induced dissociation. The major subdivisions of the Resource activity will be (1) basic research in mass spectrometry, (2) collaborative research on biomedical problems, and (3) analytical service work. The basic research activities will be concerned with studies (1) of the fundamental mechanisms involved in desorption mass spectrometry, (2) of resonance enhanced multiphoton ionization of biomolecules (3) of photon induced dissociation of biomolecules, (4) of chemical reactions of biomolecules bound to surfaces, and (5) of the enhancement of the utility of these methods for biological problems. Collaborative projects will involve studies (1) to improve the chemistry of peptide synthesis (R.B. Merrifield, Rockefeller). (2) on the identification of tumor growth markers (J. Tam, Rockefeller), (3) on the understanding of the etiology and pathobiology of scrapie and its and its related neurological disorders (L. Hood and D. Teplow), Caltech, and S. Prusiner, UCSF), (4) of protein engineering (E.T. Kaiser, Rockefeller), (5) of the structure of bacterial cell wall glycopeptides (A. Tomasz, Rockefeller), (6) of structure-function relations in proteins and peptides with interesting biological activities (S. Kent, Caltech), (7) of clinically significant mutant apolipoproteins (J. Breslow, Rockefeller), (8) of proteins, protein-linked glycans, and protein glycolipid anchors from parasites (G.A.M. Cross, Rockefeller), (9) of protein disulfide pairing (E. Breslow, Cornell Univ. Med. College), (10) of human tumor glycolipids (K.O. Lloyd, Sloan-Ketterin Institute), and (1) of the pathogenesis of diseases at the molecular level (A. Cerami, Rockefeller). The majority of these collaborative studies involve extended range MS and also extended range MS-MS.